thank you

I have an RB muffler, and I need to buy a header. Hence I am here. In case it is not clear from previous posts, I only mentioned the fact that I already have a muffler, because leafy was mentioning the possibility of getting whatever muffler I wanted.

 

This. We have searched and found little to no gains on the exhaust side. Everything we find is on the intake side, internal mods notwithstanding.

 

That isn't what I read on miata.net.

 

I guess the veracity depends on who was doing the R&D.

 

My brushed aluminum sills are worth a good 5 hp on the butt dyno.

 

Props for the chuckle!

I signed up over there and on CR to list the JR CAI that the PO had installed on the Red Car. I know I don't have a prayer of selling that trash here.

 

interesting. can you refer me to some thread with intake side discussion? I know your "famous" post on m.net... but it does not go too much into that.

thank you!

 

No one post by one person. My personal experience is that we have tried all sort of stuff on the exhaust side and found that a OTS Racing Beat header, race pipe (test pipe), midpipe and single tip exhaust flow about as much as a $2500 hand built bundle of snakes work of art header/exhaust. For fun, we tried a straight pipe. Yep, made less power than the OTS RB exhaust. While a one off Stahl or Boig big tube header for a 9000rpm 14:1 EP motor that idles at 2000rpm will likely be more effective that the OTS RB system on that example, everything else we have tried has come up with no real gains. This from a bone stock 102whp NA8 to a 400whp supercharged car and most points in between.

On the flip side, we are still finding significant power gains from the air filter to the intake port. Our CNC ported head with +2 O/S exhaust valves is about the limit of what we can produce and offer in serial production. These days, we are playing around with cam designs for a future SuperMiata cam product line. Those cams will be very affordable be cause we are making our own cast and hardened blanks. That might be 2016, who knows.

When and if someone present compelling data that shows gains on the intake side for a typical I/H/E + ECU NB engine on pump gas, we will continue to recommend and offer exhaust parts what is know to be durable, cost effective, fit perfectly, look nice and of course, make power.

 

^^^ Hopefully when your camshafts come out they'll slide right in without any expensive fancy under buckets.
Are you gonna make different profiles, 1 for low end torque and another for high revs output or is it just one profile?

 

"Slide right in" meaning just minor shim adjustments? That would mean 36mm base circle and not that interesting lift numbers before you need to machine the head for clearance.
I don't know how thick shims you can get hold of (custom is always possible) and if thick shims increase the risk och spit-out (larger max cam radius certainly do). Heavy shims does not help the springs do their job either.

Of course there can be improvements within the restrictions of "bolt on" but there are so much more freedom going to a 33mm base circle and SUBs.
But Emilio might have cracked the nut of extracting a lot from nowhere once again.

 

Probably both. We want one "drop in" cam that doesn't require buckets.That limits lobe lift to .370 with stock 36mm base circle. We have found though, that you can still get a good idle out of cams with .400-430 lift. At that lift, you need SUB's to keep from spitting shims out. Beyond that lift, it tuning gets trickier and duration gets long enough low end torque/driveability begins to disappear entirely. So probably a <.370 drop in and .425 with SUB's, caps that will require tipping valves to set lash. This is how Tomei (which makes the Maruha) kit is set up except the Tomei offers individual caps in a variety of sizes for the DIY'er.

At least thats the idea now. Many months of R&D yet to do so we'll see.

 

Lift shouldnt effect idle quality. Stock duration and intensity .400 lift cams would idle like stock cams.

 

This I got. I had read most dyno comparisons. there were not (m)any with the maruha header. big props for completing the picture.

sounds like the gains you are talking about are *not* through bolt ons though. a very different game for most people.

inexpensive cams sound like a dream...

 

But the ramps would require serious springs...
Mine idle quite nicely, at 1100 or so, if idle is all you measure.
That real torque does not come until 5k is of less importance...

 

Both bolt ons and fabricated bits. The typical DIY short ram cold side air intake cost the average person maybe $70 to build and is one of the most effective mods you can make. Either with a standalone running speed/density or extend the OEM harness and relocate the MAF. Square top is worth 6-10whp depending on the build and can be found for $400 if you hunt around a bit.

 

unfortunately I have an expensive intake of the wrong side variety. got it before I started my learning experience.

But at least I got my square top for less than $100, because Europe :-)

EDIT: ok i did a little math of intake and exhaust side non-internal stuff. I understand now. I was guess I was distracted by the port/valve/cam discussion.

 

No no, ramps would be the same it would be the flanks that would be quite steep and require quite a bit of spring. But then you wouldnt need to wait for 5k for your torque to come on.

 

I like the sound of cams at an affordable price!! I will be looking at these when they come out.

 

Looks like it's time to get creative... and figure out how to make this work on an ABS equipped NA.

That is, without removing the ABS.

Thanks for the info Emilio...

 

Check the 3d printed intake thread, they found more gains over the standard U bend so far.